NEW YORK (CBSNewYork/AP) — Democrat Bill de Blasio has widened his lead to a commanding 50 points over Republican Joe Lhota in the race for New York City mayor, according to a poll released Thursday.

De Blasio was the choice of 71 percent of likely New York voters, far ahead of the 21 percent who favor Lhota, the Quinnipiac University poll found.

De Blasio’s margin grew from 66 percent to 25 percent in the last Quinnipiac survey, which was released Sept. 19.

“These numbers say Public Advocate Bill de Blasio’s kids can start arguing over who gets the best bedroom in Gracie Mansion,” Maurice Carroll, director of the Quinnipiac University Polling Institute, said in a statement. “The flurry of negative headlines about name changes, the Sandinista visit, the Cuban honeymoon don’t seem to have any effect.”

De Blasio said that the lead was “gratifying and humbling.”

“I don’t take anything for granted,” he told 1010 WINS. “Even though this is a wonderful poll, we’ve over a month ahead and we’re going to work very hard.”

LISTEN: 1010 WINS Full Interview With Bill de Blasio On 10/3

Five percent of voters remain undecided. But 11 percent of respondents who named a candidate say there’s still a “good chance” they’ll change their mind by Nov. 5.

Among white voters, the survey shows de Blasio ahead of Lhota 55 to 40 percent. Among black voters he leads 90 to 6 percent and 79 to 10 percent among Hispanics.

Experts told CBS 2’s Dick Brennan that the numbers may suggest that many voters are not yet familiar with Lhota.

“De Blasio is riding a surge of momentum that he is riding from the waning weeks of the primary campaign. Nothing has changed in the dynamic. People don’t know who Joe Lhota is and there hasn’t been a meaningful roadblock to stop that surge,” Baruch College’s David Birdsell said.

LISTEN: WCBS 880 Full Interview With Bill de Blasio On 10/3

WCBS 880's Full Interview With Bill de Blasio

A Lhota spokeswoman downplayed the results by saying “polls go up and polls go down.”

“We remain confident that once New Yorkers learn more, they will choose Joe Lhota, a proven leader with a real plan to move New York forward,” said the spokeswoman, Jessica Proud.

Speaking in Flushing on Thursday, Lhota said he is confident he can come from behind in the polls.

As WCBS 880’s Rich Lamb reported, Lhota went on offense, saying his opponent uses cute phrases such as “A Tale of Two Cities.”

The GOP candidate blasted his opponent for not announcing a jobs plan.

“Polls go up and polls go down. While Mr. de Blasio spends his time in hiding, ducking tough questions about his ill-conceived proposals we will continue talking about Joe’s plan to create jobs, improve our schools, and keep us safe,” the Lhota campaign said in a statement issued on Thursday.

Lhota Goes On Offense Following Release Of Poll

“Bill de Blasio is essentially a political hack with no plans for the future. Doesn’t know what you need to do to negotiate. Doesn’t know what you need to do when it comes to developing plans and have alternative approaches,” said Lhota.

LISTEN:1010 WINS Full Interview With Joe Lhota On 9/30

Both campaigns have released their first general election television ad.

The Lhota campaign ad is clearly aimed at Democrats, highlighting that de Blasio and Lhota both support same-sex marriage, abortion rights and the decriminalization of small amounts of marijuana.

The de Blasio ad, meanwhile, shows uplifting clips from his primary night victory.

To improve his position as the election approaches Lhota will need to create more contrast with de Blasio, Birdsell said.

“Lhota has to do several things. He has to introduce himself to more New Yorkers to date. Second, he has to create more contrast with de Blasio,” he explained.

The poll of 1,198 likely voters was conducted Sept. 25 to Oct. 1. The margin of error is plus or minus 2.8 percentage points.